1. Field of the Invention
This invention relates to an exercise device, and in particular, an exercise device which is used to exercise one's back in a safe manner for therapeutic purposes and also to measure, for example, the torque generated by the muscles so exercised.
2. Background Discussion
There is a need for equipment which will safely measure the work, power, endurance and torque generated by the human back muscles during exercise. Insufficient data now makes it extremely difficult to determine what is the normal performance of back muscles for patients of differing sizes and weights. Ideally, a back exerciser coupled to suitable electronic measuring and recording instrumentation would enable one to collect data on the normal performance of back muscles from a broad sampling of patients and then use this data in evaluating an individual patient's performance under similar test conditions.
Conventional back exercisers which are currently being sold are designed so that the person using the exerciser assumes a generally vertical position and bends at the waist. During exercise musclar performance of the back muscles is measured by a conventional dynamometer. Torque, power, work and endurance are measured and recorded, and these measurements provide quantitative data indicating how the back muscles are performing and this data is then analyzed to functionally evaluate the condition of the person's back muscles.
There are two problems associated with such conventional exercisers. First, as soon as the person begins, to bend at the waist, the weight of the apparatus, once the apparatus moves off the vertical, becomes a factor which prevents an accurate measurement. The heavier the equipment, the greater the momentum generated by the person bending at the waist. This momentum prevents obtaining a truly accurate measurement of the muscular performance. Secondly, because the person has assumed a vertical position and then bends to move from this vertical position, carrying the exercise equipment on his back, the weight of the exercise equipment could cause injury. In other words, the person may strain his or her back muscles which are being stretched under the weight of the exercise equipment and the weight of the torso.